Java enum values are permitted to have value-specific class bodies, e.g. (and I hope this syntax is correct…) public enum MyEnum { A { void doSomething() { … } }, B { void doSomethingElse() { … } }; } This will generate inner classes representing the class bodies for A and B. These inner classes … Read more
Create new folder Views/Shared/DisplayTemplates Add empty Partial View named Enum, to the folder Replace Enum View code with: @model Enum @if (EnumHelper.IsValidForEnumHelper(ViewData.ModelMetadata)) { // Display Enum using same names (from [Display] attributes) as in editors string displayName = null; foreach (SelectListItem item in EnumHelper.GetSelectList(ViewData.ModelMetadata, (Enum)Model)) { if (item.Selected) { displayName = item.Text ?? item.Value; } … Read more
Obviously, the lambda version is far more readable. Not only is it shorter, it allows a reader to see the the implementation operator at the first glance in the constructor. Imagine you want to extend the enum to support int calculation as well… From a performance point of view you are exchanging the anonymous enum … Read more
Anything but return this == other would be counter intuitive and violate the principle of least astonishment. Two enum constants are expected to be equal if and only if they are the same object and the ability to override this behavior would be error prone. Same reasoning applies to hashCode(), clone(), compareTo(Object), name(), ordinal(), and … Read more
Based on @scottb solution I made this, tested against hibernate 4.3: (no hibernate classes, should run on JPA just fine) Interface enum must implement: public interface PersistableEnum<T> { public T getValue(); } Base abstract converter: @Converter public abstract class AbstractEnumConverter<T extends Enum<T> & PersistableEnum<E>, E> implements AttributeConverter<T, E> { private final Class<T> clazz; public AbstractEnumConverter(Class<T> … Read more
Given enum Foo {Bar=0,Baz,…,Last}; you can iterate the elements like: for(int i=Bar; i<=Last; i++) { … } Note that this exposes the really-just-an-int nature of a C enum. In particular, you can see that a C enum doesn’t really provide type safety, as you can use an int in place of an enum value and … Read more
Maybe writing the values in hexadecimal (or binary) helps 🙂 enum { kCGDisplayBeginConfigurationFlag = (1 << 0), /* 0b0000000000000001 */ kCGDisplayMovedFlag = (1 << 1), /* 0b0000000000000010 */ kCGDisplaySetMainFlag = (1 << 2), /* 0b0000000000000100 */ kCGDisplaySetModeFlag = (1 << 3), /* 0b0000000000001000 */ kCGDisplayAddFlag = (1 << 4), /* 0b0000000000010000 */ kCGDisplayRemoveFlag = (1 … Read more
NOTE: This has been resolved in MVC 4. If upgrading to MVC 4 is a viable option for your project then that is all you have to do in order to begin model-binding to enums. That said, here is the workaround for MVC 3 if you still need it. The issue is with the default … Read more
So, is there a way to avoid having to type CatState:: all the time? Not before C++20. Just as there’s no equivalent for having to type ClassName:: for static class members. You can’t say using typename ClassName and then get at the internals. The same goes for strongly typed enums. C++20 adds the using enum … Read more
You can make a convert to each enum, like this: class Converters { @TypeConverter fun toHealth(value: String) = enumValueOf<Health>(value) @TypeConverter fun fromHealth(value: Health) = value.name } Or if you prefer store it as SQL integer, you can use ordinal too: class Converters { @TypeConverter fun toHealth(value: Int) = enumValues<Health>()[value] @TypeConverter fun fromHealth(value: Health) = value.ordinal … Read more